Autism spectrum disorders (ASDs) are complex neurodevelopmental disabilities characterized by repetitive/stereotypic behaviors and deficits in communication and social interaction. Recent studies highlight striking neural and peripheral immune dysregulation in autistic individuals. Moreover, a significant subset of ASD children exhibit gastrointestinal (GI) complications, including increased intestinal permeability and altered composition of intestinal microbiota. Furthermore, antibiotic treatment and restricted diets are reported to improve behavioral symptoms in some ASD children (reviewed by Buie et al., 2010).